Go online to the Illinois Department of Agriculture website — agr.state.il.us — to view maps of gypsy moth treatment sites by county. Click on “Gypsy Moth” under “Hot Topics” in the middle of the homepage.

FREEPORT — The Illinois Department of Agriculture will be treating 38,000 acres in northern Illinois next week to protect vegetation from gypsy moths.

The gypsy moth is an invasive forest pest that preys primarily on the leaves of oak trees, though it feeds on nearly 250 different types of trees and shrubs.

When the leaves are attacked, the tree’s ability to transport nutrients is diminished. Trees are left vulnerable to diseases, native pests and environmental conditions. Large populations of the moths can cause severe defoliation, which can kill the tree.

To treat, a pheromone will be released aerially over areas in Boone, Cook, DuPage, Kane, Kendall, LaSalle, Stephenson, Will and Winnebago counties. The pheromone will cause male moths to smell female moths everywhere, disrupting their ability to actually find mates. The treatment is a relatively quick application and should be done in one day. It will begin Monday, weather permitting.

Walter Lender, manager at Ron Lender Tree and Landscape in Freeport, is unfazed by the gypsy moths’ appearance in the area because his business treats the trees for it every year.

However, Freeport Park District officials have concerns.

“It’s another attack on the trees,” Executive Director Jack Carey said. “We’ve got vehicles hitting trees in our parks, emerald ash borer infesting them, oak welt, drought, wind, floods. We’re losing trees faster than we can plant them, and now we have to worry about gypsy moths. It’s a frustrating situation to us. It’s disheartening, but we’ll deal with it as best we can. Luckily, the state is stepping in to battle it with the spraying.”

Scott Schirmer with the Illinois Department of Agriculture said the state will do what it can to protect area trees, though treatment might be difficult.

“Most people, at this point, hopefully understand the importance of trees in the natural setting,” he said. “They provide oxygen and flood prevention, help with heating and cooling homes in the urban setting, they sequester water and pollution and are critical from a health standpoint.

“(Gypsy moths are) a nuisance for residents and home owners, but treatment is important when trying to keep the environment healthy.”